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Biomedical subjects

L Olsen

Publications and source records attributed to L Olsen.

At least 91 records · Page 5Linked to original sources
PubMed1989

Single-dose versus six-day therapy with sulfamethizole for asymptomatic bacteriuria during pregnancy. A prospective randomised study.

Single-dose versus conventional six-day therapy with sulfamethizole for asymptomatic urinary tract infection in pregnant women was investigated in a prospective, randomised open study. During a nine-month period 4,274 pregnant women were screened for significant bacteriuria, which was found in 123 (2.9%), of whom only five had symptoms of urinary tract infection. Seventy-nine of the patients had a second urine culture performed, revealing significant counts of the same bacteria in only 41. These 41 patients were randomly allocated to one of the two treatment groups. Control urine cultures one week and 4-6 weeks after start of treatment revealed the same cure rates of approximately 50% in both groups. Single-dose treatment is not inferior to conventional therapy; future study is needed to find the best single-dose regimen.

Bacteriuria↗
PubMed1988

S-100 protein and neuron-specific enolase in amniotic fluid as markers of abdominal wall and neural tube defects in the fetus.

The aim of this study was to determine whether there is increased leakage of neuron-specific enolase (NSE) and S-100 protein into amniotic fluid in pregnancies with neural tube defects, since both these proteins are produced by neural tissue, and to compare the value of these substances for detecting such defects with that of the more conventional techniques of alpha-fetoprotein (AFP) and acetylcholinesterase (AChE) gel electrophoresis. Amniotic samples from 25 mid-pregnancies (15-17 weeks' gestation) with neural tube defects (14 with open spina bifida and 11 with anencephaly) and from seven mid-pregnancies with abdominal wall defects were compared with a control material consisting of 80 amniotic fluid samples from 80 consecutive mid-pregnancy amniocenteses, with normal karyotypes and AFP concentrations. All of the above cases of abnormalities were primarily detected through increased AFP levels in the amniotic fluid. Amniotic fluid samples from 13 pregnancies with fetuses with autosomal chromosomal abnormalities and seven amniotic fluid samples contaminated with blood were also included in the investigation. It is concluded from the results that the conventional AFP assay combined with AChE gel electrophoresis is the best method for screening amniotic fluid for neural tube defects and defects of the abdominal wall. Neither NSE nor S-100 assay alone proved to be superior for the detection of these cases in mid-trimester amniotic fluid. The S-100 assay, however, could give additional information in cases where AChE gel electrophoresis is not decisive; for example, in samples contaminated with blood.

Abdominal Muscles↗
PubMed1988

Hemobilia in childhood.

During a 10-year period we have encountered three cases of hemobilia among children after blunt abdominal trauma. All patients had the classical symptoms with varying degrees of severity. One of the patients, a 5-year-old boy, had several episodes of severe gastrointestinal bleeding, abdominal pain, and jaundice during a 2-month period. He was treated with selective arterial embolization of the left hepatic artery. The symptoms ceased instantly, and the patient has remained healthy during an observation period of more than 2 years. In cases of hemobilia, selective arterial embolization is a safe method with no serious complications. Arterial collaterals develop very quickly and the risk of liver dysfunction is small. We suggest that embolization of hepatic arteries may be the treatment of choice even in small children with hemobilia.

Athletic Injuries↗
PubMed1988

Back-leak of pelvic urine to the bloodstream.

The aim of the present investigation was to measure the back-leak of pelvic urine to the blood circulation. In normopenic hydronephrotic, dehydrated hydronephrotic and dehydrated control kidneys the back-leak was estimated from a servocontrolled machine which regulated infused saline to keep a present pelvic pressure constant. The disappearance of fluid from the renal pelvis could be measured at different pressure levels, and a pressure-dependent outflow of fluid was found. From these measurements a back-leak conductance could be calculated which proved to be independent of pressure. In the lower pressure range (15-20 mmHg) there was a significantly lower conductance in the dehydrated controls compared with the dyhydrated hydronephrotic kidneys, while in the higher pressure range (25-30 mmHg) no difference was found. From electron microscopical studies the pyelorenal back-leak of fluid in both hydronephrotic and control animals seemed to be most pronounced in the fornix region, as documented by a heavy presence of horseradish peroxidase in the intracellular spaces there. Other experiments with radioactively labelled inulin, which was injected into the pelvic cavity, indicated that most of the back-leak occurred via the renal blood vessels and not through the lymphatic system. The importance of this back-leak was evident from the measurements of the total kidney glomerular filtration rate (GFR) at a slightly increased pelvic pressure, where some of the urine with radioactive tracer flows back to circulation. The back-leak of pelvic urine could also affect the concentration mechanism by removing diluted urine which had flowed over the renal papilla, and through water and urea diffusion increased papillary interstitial osmolarity.

Animals↗
PubMed1988

Cloning and expression in Escherichia coli of the gene for extracellular phospholipase A1 from Serratia liquefaciens.

From a genomic library of Serratia liquefaciens, a cloned DNA fragment comprising a two-gene operon was isolated and expressed in Escherichia coli. One of the gene products was identified as a phospholipase A1, and the enzyme was found to be excreted to the outer environment from S. liquefaciens as well as from E. coli. Both genes were sequenced, and the relationship between open reading frames in the DNA sequence and in vitro-expressed polypeptides was established. The length of the phospholipase polypeptide was found to be 319 amino acids. In the amino-terminal end of the coding sequence was a stretch of about 20 hydrophobic amino acids, but, in contrast to consensus signal peptides, no basic residues were present. The length of the second polypeptide was 227 amino acids. It was found that expression of the phospholipase gene in both E. coli and S. liquefaciens was growth phase regulated (late expression).

Amino Acid Sequence↗
PubMed1988

Pressure and flow measurements in the partially obstructed ureter of the rat.

Hydronephrosis in man or experimental animals can be caused by an increased ureteral flow resistance. This condition can in the long run prove harmful to renal function. We compared two ways of measuring ureteral flow resistance in animals with and without a ureteral hindrance, the hindrance being induced by embedding the ureter in the psoas muscle. One needle connected via catheters to a pressure recording system and another connected to a pump system were introduced through the parenchyma into the renal pelvis. Experiments were carried out with two procedures: 1) infusion of 0.5 ml x min-1 of saline into the renal pelvis was performed while recording the pressure response; 2) a servocontrolled pump system was used which regulated the flow introduced into the renal pelvis to keep a preset pressure at a constant level. In the first group of experiments we did not establish a steady-state pressure despite 20-30 min of infusion. The result from the second series of experiments indicated that steady-state flow measurements could be achieved at the different pressure levels between zero and 30 mmHg. A good linear relationship between pressure and flow was found, even though a considerable hysteresis was observed. Furthermore, a reduced flow resistance down to a certain level at increased pressure was also recorded. As expected, the resistance to flow was significantly lower in the control than in the hydronephrotic animals. In order to investigate the diagnostic ability of the linear relationship between pressure and flow, prediction regions for one future animal were calculated. It seemed possible that determination of the whole pressure-flow relationship in the pressure range between zero and 30 mmHg will prove useful to determine the flow hindrance in hydronephrotic animals.

Animals↗
PubMed1987

Properties and mechanism of action of eukaryotic 3-methyladenine-DNA glycosylases.

3-Methyladenine-DNA glycosylase activities have been identified in all eukaryotic cell systems studied. Some of the results from these studies are reviewed here. The enzymes possess molecular weights between 24 X 10(3) and 34 X 10(3), they have a broad pH optimum at approximately pH 8, require double-stranded DNA and act in the absence of any cofactors. The enzyme can excise several different methylated bases from DNA such as 3-methyladenine, 7-methylguanine and 3-methylguanine. The specific activity of this DNA glycosylase in mouse L-cells was found to be a function of the proliferative state of the cell. In vitro quantification of this DNA repair activity in synchronized mouse L-cells suggests that it is regulated within a defined temporal sequence prior to the onset of DNA replication. Using DNA fragments of defined sequences it was observed that the efficiency of removal of the methylated bases is sequence-dependent.

Animals↗
PubMed1986

Differential effects of in vitro heating on rat sciatic nerve branches and spinal nerve roots.

Locally applied heat induces nerve conduction block. Conflicting observations have been made regarding the relation of fiber conduction velocity to heat sensitivity. This study utilized sciatic nerve branches and spinal nerve roots which were heated until a substantial conduction block occurred. The results indicated that sensory fibers conducting at greater than 40 m/s are more heat-sensitive than motor fibers of the same conduction velocity.

Action Potentials↗
PubMed1986

Immunocytochemical demonstration of neuron-specific enolase for differential diagnosis of retroperitoneal tumours in children.

Six patients with malignant retroperitoneal tumours causing considerable diagnostic difficulties are reported. In a retrospective investigation the presence of neuron-specific enolase (NSE) was analysed immunocytochemically in specimens of these tumours. In all the patients who had finally got the definite diagnosis neuroblastoma, tumour specimens had a strong reaction for NSE whereas all other tumours did not react. An analysis of NSE already at the primary investigation could have led to an earlier definite diagnosis.

Child↗
PubMed1986

Polymorphonuclear neutrophil function and infections following splenectomy in childhood.

22 subjects were controlled 3-23 yr after splenectomy due to childhood trauma (10), idiopathic thrombocytopenic purpura (9) or congenital spherocytosis (3). The control comprised a history of infections, physical examination, routine hematologic values, determinations of serum immunoglobulins, evaluation of complement activities, cultivations from throat and nasopharynx and polymorphonuclear neutrophil (PMN) function tests. 14 patients (63%) had increased susceptibility to recurrent bacterial infections (SBI), most often tonsillitis. All these patients also had abnormal PMN function. The other 8 patients with normal susceptibility to infections showed essentially normal PMN function. There were no differences between these groups with regard to indication for splenectomy, age at splenectomy or the time interval after splenectomy. This abnormal PMN function may explain the raised susceptibility to infections.

Adolescent↗
PubMed1985

Partial ureteric obstruction in weanling rats. I. Long-term effects on the renal morphology.

Partial obstruction of one ureter was created in weanling rats (3 weeks old) and its effects were studied after 3, 6, and 9 weeks. Within 3 weeks, a considerable hydronephrosis had appeared, which did not progress with time. No effect on parenchymal weight was observed, either on the obstructed side or on the contralateral, intact one. Histological examination revealed a marked deformation of the papilla in about 25% of the hydronephrotic kidneys and evidence of chronic pyelonephritis in 40%. However, the inflammatory changes were restricted to the attenuated circumhilar 'edges' of the parenchyma, thus involving only a minor portion of the kidney. The body weight of the animals obstructed for 9 weeks was 12% lower than that of normal, sham-operated controls. In summary, the effect on the renal parenchyma of partial ureteric obstruction, created in the weanling period, was relatively discrete and less pronounced than when obstruction is performed in the neonatal period.

Animals↗
PubMed1983

Neuron-specific enolase as a differential marker in a case of retroperitoneal tumour.

In some cases of retroperitoneal tumour, preoperative investigations fail to conclusively differentiate between neuroblastoma and Wilms' tumour. Diagnostic difficulties can be encountered also intraoperatively, and even the histopathological presentation can be equivocal. According to earlier results, neuron-specific enolase (NSE) in tumour extract can be used as a marker for neuronal tissue and thus offers a new diagnostic criterion differing neuroblastoma from e.g. Wilms' tumour. This paper presents a case of Wilms' tumour where a low content of NSE in the tumour extract correctly indicated a non-neuronal tumour, whereas preoperative presentation and primary histopathology suggested a neuroblastoma.

Child↗
PubMed1983

Inulin single injection clearance. Microsample technique useful in children for determination of glomerular filtration rate.

The agreement between single injection inulin (polyfructosan) clearance and two reference methods for glomerular filtration rate (GFR) determination, namely standard inulin constant infusion clearance and 51-Cr-EDTA single injection clearance, was investigated. Studies were also made to see whether different results were obtained when capillary and venous blood samples were used in the single injection clearance method. The investigation was made in children from one year of age, adult patients and volunteers. For the single injection technique with inulin or 51-Cr-EDTA, five to seven blood samples were taken in a period of up to 180 min after injection. A bi-exponential plasma disappearance curve was used for calculations of single injection clearances. Good agreement was obtained between venous inulin single injection clearance on the one hand, and standard inulin clearance (correlation coefficient r = 0.86) and 51-Cr-EDTA single injection clearance on the other (r = 0.85). With use of capillary blood samples in inulin single injection clearance, similar good agreement was obtained both with venous 51-Cr-EDTA and with venous inulin single injection clearance (r = 0.85 and r = 0.89 respectively). From these results we conclude that inulin single injection clearance is a reliable method for GFR determinations. This method is recommended, especially in children, as capillary blood samples can be used.

Adolescent↗
PubMed1983

Complications in the treatment of hydrocephalus in children. A comparison of ventriculoatrial and ventriculoperitoneal shunts in a 20-year material.

Two homogenous materials of hydrocephalic children operated upon during a 20-year period (1961-1980) are compared. During the first half of the period the ventriculoatrial shunt was the only type used in 103 patients. After that there was a change to the ventriculoperitoneal shunt which was used in 104 patients, whereof 35 were converted from ventriculoatrial to ventriculoperitoneal shunts. Thus the material consists of 172 patients. The complications were less serious and the mortality rate much lower with the ventriculoperitoneal method. The revision rate, however, was about the same for both types of operation, but the revisions and the operative procedure for peritoneal shunts were generally much more simple and more rapidly performed. Therefore it is our opinion that in children the ventriculoperitoneal route is preferable to the ventriculoatrial route. With better knowledge of the underlying cause of distal obstructions in the former route we think that it will be possible to reduce the complication and revision rates even further.

Cerebrospinal Fluid Shunts↗